Apparatus on extrusion worm presses for eliminating the texture in ceramic masses



May 1, 1962 E. BRUCKNER 3,

APPARATUS ON EXTRUSION WORM PRESSES FOR ELIMINATING THE TEXTURE IN CERAMIC MASSES Filed Feb. 3, 1960 FIG. I

INVEZNTOR. ERNST BRUCKNER A TTORNE Y United States Patent APPARATUS ON EXTRUSION WORM PRESSES FOR ELIMINATHIG THE TEXTURE IN CERAMIC MASSES Ernst Briickner, Selb, Germany, assignor to Gebruder Netzsch, Maschinenfabrik, Selb, Germany Filed Feb. 3, 1960, Ser. No. 6,551 8 Claims. (Cl. 25-14) Texture destroying apparatus are known in which a swing screen arranged transversely to the feed direction of the mass string, following the press worm, reduces the viscosity of the ceramic mass 'by radial oscillations of high frequency and thus eliminates the texture produced by the press worm.

Such swing screens are either driven from outside, which requires considerable power and attachments on the press, or are subjected to reciprocating and tipping movements through the hollow worm shaft by means ofa cam arranged outside the press.

From the mechanical viewpoint, however, the continuous change of direction has a very unfavourable effectespecially in view of the high frequencies which are necessarybecause the reversal of the direction of rotation takes place precisely when the momentum of the swing screen is greatest. The cam drive and the rod system are thereby subjected to considerable stress resulting in heavy wear. The rod extending through the worm shaft and serving as carrier for the swing screen must also be of relatively large diameter in order to be able to transmit the driving force from the cam and to take up the axial pressure exerted on the swing screen. In view of the limited diameter of the hollow shaft, however, bearings with small dimensions can only be fitted with the result that they are also subject to heavy wear. The sealing of the rod, which does not rotate, against the rotating hollow shaft is moreover difficult to carry out in view of the high mass pressure occurring in the cylinder and it is difficult to prevent the mass from penetrating the front hearing, which leads to premature destruction thereof.

According to the invention, however, a rotating oscillator is mounted in the hollow worm shaft. As a result the radially oscillating screen is no longer subjected to reciprocation but only to rotary movement. It is known per se in worm extrusion presses to impart rotary motion to texture destroyers constructed as arms cutting through the material, but the effect of the rotating arms cannot be compared with the effect of a rotating and also radially sw'mging screen, because the rotary movement of the arms alone, owing to the differences in velocity, produces fresh textures in the mass. The drive of the oscillator is, in a further embodiment of the invention, effected by a flexible shaft or a Cardan shaft which extends through the worm shaft. External rod systems are dispensed with entirely, so that considerable simplification and more reliable operation are attained.

By the rotary oscillations of the screen, the mass is worked over the entire cross-sectional area and, by the continuous displacement of the passage apertures in the swing screen, the formation of longitudinal textures is prevented. In view of the short length of the oscillator, the oscillator shaft need only be of small diameter, with the result that it can be fitted in amply dimensioned bearings which can likewise be sealed perfectly. As the hollow shaft and the oscillator rotate together they can be sealed in relation to each other in a perfect manner.

As the oscillations are only generated at the point where they are required, ill effects on the machine itself are reduced to a minimum.

Apparatus according to the invention is illustrated by way of example in the accompanying drawings, in which- FIG. 1 is a longitudinal section through the shaft of the press worm with the apparatus fitted therein, and

FIG. 2 shows the extrusion press itself with the apparatus fitted therein.

On the discharge end of the worm shaft a, constructed as a hollow shaft, a cap nut b is fitted for holding a ring 0 which serves for accommodating the oscillator. The sleeve d of the oscillator is for this purpose made of larger diameter at the end e, whereby the side bearing against the ring c is of cup-shape and adapted to the inner convex side of the ring. In the interior of the sleeve d a shaft g, running in bearings f, is arranged, on which an unbalanced disc h is mounted. If the shaft g is now rotated by a flexible shaft it connected to it by means of a coupling i, gyratory motion is imparted by the unbalanced disc h to the sleeve d together with the swing screen m fitted on its extended end 1, whereby the sleeve, being guided by the ring c, is moved in the elastic joint n.

The flexible shaft k is connected at its other end by means of a coupling 0 to a driving shaft p which is mounted in the housing q rigidly connected with the hollow shaft a and directly driven by a V-belt drive r from a motor which is not shown on the drawing.

In addition to the embodiment shown, various modifications are possible within the scope of the invention; thus, for example, the unbalanced disc h can be arranged at the other end of the sleeve and ball bearings can be provided instead of the ring 0 and the elastic joint n.

The invention can also be applied on presses with vertically arranged press worms.

I claim:

1. Apparatus on extrusion worm presses for eliminating the texture in ceramic masses, comprising in combination with the worm and a hollow worm shaft, a screen radially oscillatable with high frequency arranged following said worm transversely to the direction of the feed of the string of mass and driven through said hollow shaft, and a rotary oscillator mounted on the discharge end of said worm in the hollow worm shaft and subjected to rotary radial oscillations.

2. Apparatus as set forth in claim 1, wherein a flexible shaft extending through the worm shaft effects the drive of the oscillator, said shaft being directly connected by a coupling with a shaft mounted in the hollow worm shaft and directly driven from a motor by means of a V-belt drive.

3. Apparatus as set forth in claim 2, wherein the oscillator is movably mounted in an elastic joint of the hollow worm shaft and has a built-in shaft with unbalance for producing the oscillations.

4. A texture-destroying arrangement for worm presses including a press cylinder having a worm therein, comprising a rotatable and radially-oscillatable stirrer means including a screen arranged transversely to the direction of the feed of the string mass passing through said worm and adjacent the discharge end of said worm, drive means for rotating said stirrer means, and means for radially oscillating said stirrer means.

5. A texture-destroying arrangement for worm presses including a press cylinder having a worm therein, comprising a radially-oscillatable screen arranged transversely to the direction of the feed of the string mass passing through said worm following said worm and means including a rotary oscillator for rotating said screen and providing said radially-oscillatable movement thereof.

6. A texture-destroying arrangement for worm presses having a press cylinder and a worm in said cylinder, comprising a rotatable and radially-oscillatable stirrer means including a screen arranged transversely to the direction of the feed of the string mass passing through said worm and adjacent the discharge end of said worm,

said Worm having a hollow shaft, and means extending through said hollow shaft including a rotary oscillator means mounted within said hollow shaft at the discharge end of said worm for driving said stirrer means and providing the radially oscillatory movement thereof.

7. A texture-destroying arrangement for worm presses as defined in claim 6, wherein said rotary oscillator means includes a sleeve having one end movably secured within said hollow shaft adjacent the discharge end of said worm, said screen being secured to the outer end of said sleeve, a drive shaft, and unbalanced weight means secured to said shaft.

8. A texture-destroying arrangement for worrn presses as defined in claim 7, wherein the means for movably securing said sleeve-within said hollow shaft includes a ring having a cup-shaped side, the end of said sleeve extending into said hollow shaft and said cup-shaped side of said ring forming essentially a ball-and-socket joint, and an elastic joint secured between the sides of said hollow shaft adjacent the discharge end of said worm and said sleeve.

Stober May 10, 1949 Lindkuist May 20, 1952 

1.
 5. A TEXTURE-DESTROYING ARRANGEMENT FOR WORM PRESSES INCLUDING A PRESS CYLINDER HAVING A WORN THEREIN COMPRISING A RADICALLY-OSCILLATABLE SCREEN ARRANGED TRANSVERSELY TO THE DIRECTION OF THE FEED OF THE STRING MASS PASSING THROUGH SAID WORM FOLLOWING SAID WORM AND MEANS INCLUDING A ROTARY OSCILLATOR FOR ROTATING SAID SCREEN AND PROVIDING SAID RADIALLY-OSCILLATABLE MOVEMENT THEREOF. 